The trial opened Tuesday of four top South Sudanese leaders accused of treason for allegedly attempting to topple President Salva Kiir after fighting broke out in December.
The four are Pagan Amum, former secretary general of the ruling party, ex-national security minister Oyai Deng Ajak, former ambassador to the US Ezekiel Lol Gatkuoth, and ex-deputy defence minister Majak D'Agoot.
The four, who spoke in the Juba court only to confirm their names but who have in the past denied all charges, were dressed in suits and appeared to be in good health.
The four were read 11 charges, including the main charge of treason, defence lawyer Ajo Noel said.
"It is too early for us to tell what the case will be," Noel told AFP.
"We want to go through all that the judges will say, and we will see what comes out of it."
The courtroom, which was crowded with spectators including foreign diplomats, was surrounded by armed security officers.
South Sudan's government has been at war with rebel groups since December 15, when a clash between troops loyal to Kiir and those loyal to sacked vice president Riek Machar snowballed into full-scale fighting across the world's newest nation.
Thousands of people have been killed in the conflict.
Eleven ex-officials were arrested, while Machar -- who denied any coup plot -- fled.
However, seven of those intially arrested were released without charge in Kenya in January.
The release of all the prisoners has been a key demand of the rebels.
The two sides signed a ceasefire agreement on 23 January, but heavy fighting has continued.
Stalled peace talks in neighbouring Ethiopia, which have made little progress, are due to resume on March 20.
Over 930,000 civilians have fled their homes since fighting began, including over quarter of million leaving for neighbouring nations as refugees, according to the United Nations.